Reviewed-by: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1264)

Fix some code examples, trailing whitespace
Fix TBA sections in verify, remove others.
Remove empty sections
Use Mixed Case not ALL CAPS in head2
Enhance doc-nits script.
Remove extra =cut line
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

It is up to the caller of SSL_dane_tlsa_add() to take appropriate
action when no records are added successfully or adding some records
triggers an internal error (negative return value).

With this change the caller can continue with PKIX if desired when
none of the TLSA records are usable, or take some appropriate action
if DANE is required.

Also fixed the internal ssl_dane_dup() function to properly initialize
the TLSA RR stack in the target SSL handle.  Errors in ssl_dane_dup()
are no longer ignored.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

MR: #2452

Reviewed-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>

As documented both SSL_get0_dane_authority() and SSL_get0_dane_tlsa()
are expected to return a negative match depth and nothing else when
verification fails.  However, this only happened when verification
failed during chain construction.  Errors in verification of the
constructed chain did not have the intended effect on these functions.

This commit updates the functions to check for verify_result ==
X509_V_OK, and no longer erases any accumulated match information
when chain construction fails.  Sophisticated developers can, with
care, use SSL_set_verify_result(ssl, X509_V_OK) to "peek" at TLSA
info even when verification fail.  They must of course first check
and save the real error, and restore the original error as quickly
as possible.  Hiding by default seems to be the safer interface.

Introduced X509_V_ERR_DANE_NO_MATCH code to signal failure to find
matching TLSA records.  Previously reported via X509_V_ERR_CERT_UNTRUSTED.

This also changes the "-brief" output from s_client to include
verification results and TLSA match information.

Mentioned session resumption in code example in SSL_CTX_dane_enable(3).
Also mentioned that depths returned are relative to the verified chain
which is now available via SSL_get0_verified_chain(3).

Added a few more test-cases to danetest, that exercise the new
code.

Resolved thread safety issue in use of static buffer in
X509_verify_cert_error_string().

Fixed long-stating issue in apps/s_cb.c which always sets verify_error
to either X509_V_OK or "chain to long", code elsewhere (e.g.
s_time.c), seems to expect the actual error.  [ The new chain
construction code is expected to correctly generate "chain
too long" errors, so at some point we need to drop the
work-arounds, once SSL_set_verify_depth() is also fixed to
propagate the depth to X509_STORE_CTX reliably. ]
Reviewed-by: NRich Salz <rsalz@openssl.org>

This avoids explicit double spaces between sentences.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Also s/s/ssl/ as appropriate in the code example.

Suggested by Claus Assmann.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reported-by: Claus Assmann
Reviewed-by: NRich Salz <rsalz@openssl.org>

Also tweak some of the code in demos/bio, to enable interactive
testing of BIO_s_accept's use of SSL_dup.  Changed the sconnect
client to authenticate the server, which now exercises the new
SSL_set1_host() function.
Reviewed-by: NRichard Levitte <levitte@openssl.org>